#include<iostream>
#include <iomanip>
#include <algorithm>
using namespace std;
#define N 100
int main() {
    int h, m, k;
    char c;
    while (cin >> h >> c >> m >> k) {
        k = m + k;
        m = k % 60;
        k = k / 60;
        h = h + k;
        h = h % 24;
        printf("%02d:%02d\n", h, m);
    }
    return 0;
}
